Escapement mechanism for watches and marine clocks.



W E PORTER ESGAPEMENT MECHANISM FOR WATCHES AND MARINE CLOCKS.

Patented July 23, 1912.

APPLICATION FILED APR.21, 1911.

UNITED STATES PATENT FFTCE.

WILSON E. PORTER, O1? NEW HAVEN, CONNECTICUT, ASSIGNOR TO NEW HAVENCLOCK CO., OF NEW HAVEN, CONNECTICUT, A CORPORATION.

ESCAPEMENT MECHANISM FOR WATCHES AND MARINE CLOCKS.

Specification of Letters Patent.

Application filed April 21, 1911.

Patented July 23, 1912.

Serial No. 622,543.

To all whom it may concern:

Be it known that I, vVILsoN E. PORTER, a citizen of the United States,residing at New Haven, in the county of New Haven and State ofConnecticut, have invented a new and useful Improvement in EscapementMechanism for Watches and Marine Clocks; and I do hereby declare thefollowing, when taken in connection with the accompanying drawings andthe letters of reference marked thereon, to be a full, clear, and exactdescription of the same, and which said drawings constitute part of thisspecification, and represent, in

Figure 1 a plan view of a balance-wheel and escapement-lever, the formerbeing provided with a flattened wire impulse-pin con structed inaccordance with my invention. Fig. 2 a view on a larger scale showingthe pin in the fork of the lever. Fig. 3 a broken view in verticalsection on the line a?) of Fig. 2. Fig. 4 a detached plan view of thepin. Fig. 5 a view of the pin in transverse section.

Formerly the escapements of watches were provided with impulse-pins ofruby, sapphire, garnet, agate and glass installed by means of shellacafter having been first ground into flattened or oval form, but suchpins were far too expensive and delicate to be used in the cheap watchesnow made in such large quantities, and some substitute had to be foundfor them. Recently metal impulse-pins made by cutting up round wire intosuitable lengths have been employed. The round wire itself, of course,is inexpensive, but the manual pointing of the wire to permit the pinsto be driven is a delicate and somewhat expensive operation. Moreoverround pins are objectionable on account of the expense of adjusting theescapements in which they are used with the accuracy required to insurethe clearance of the pins from the curved impulse-faces of the impulseslots of the forks of the escape- Inent levers when the pins enter theslots. This delicate adjustment has not only to be made in the firstplace, but maintained to make the watch run and secure good results. Toobviate the necessity of the accurate adjustments required, asdescribed, with round pins, such pins were filed away into half roundform after being driven into the balance-wheel, whereby although expenseof adjustment was saved, additional expense was involved in filing intoflattened form those portions of the pins entering the impulse slots ofthe escapement-lever forks. In this connection it should be made clearthat a full round pin while not more expensive or difficult to installrequires that the entire escapement of which it is a feature, shall beadjusted with far more accuracy, and maintained in far more accurateadjustment, than a pin having that portion of it entering the slot inthe fork flattened to insure ample clearance.

The object of my present invention is to produce at a low cost formanufacture a wire impulse-pin having all the functional advantages offlattened or oval stone pins and of those wire pins which are milledafter they are mounted, and yet made complete before being set, and nomore expensive to set than any other wire pin.

W'ith these ends in view my invention consists in an impulse-pin havingcertain details of construction as will be hereinafter described andpointed out in the claims.

In carrying out my invention as herein shown, I employ a straight, wireimpulsepin 2 having fiat opposite faces 3, symmetrically rounded edges4, and convexed ends 5, such pins being produced by rolling and thusflattening round drawn wire, which is then cut up into pins havingrounded ends so that either end may be conveniently inserted into a hole6 formed for the reception of the pin in the cross-arm 7 of an ordinarybalance-wheel 8 which is mounted upon a balance staff 9, the said pinbeing located flatwise or at a right angle to the longitudinal axis ofthe arm 7. As thus positioned the rounded edges of the pin co-act withthe straight, parallel opposite walls of the inner end of theimpulse-slot 10 which is formed in the fork 12 of the escapement-lever13 which is mounted. as usual, upon a verge-arbor 14-, and furnishedwith escapement-pins 15 co-acting with the teeth of the escapement-wheelwhich is not shown. The outer ends of the side walls of the slot 10 aresymmetrically curved outward away from each other, but the curvedportions of these walls do not ordinarily co-act with the rounded edgesl of the impulse-pin 2.

I claim In an escapement mechanism for watches and marine clocks, thecombination with a balance-wheel having a cr0ssarm, of anescapement-lever having a fork formed with an impulse-slot the innerportions of the side walls of which are straight and parallel, and astraight, flat wire impulse-pin having fiat faces and symmetricallyrounded edges, and convexed or rounded ends, the said pin being driveninto the said cross arm with its fiat faces at a right angle to thelongitudinal axis thereof, whereby its symmetrically rounded edges arein position for co-action with the straight opposite walls of theimpulse-slot in the escapementlever.

In testimony whereof, I have signed this specification in the presenceof two subscribing Witnesses.

WILSON E. PORTER.

Vitnesses FREDERIO C. EARLE, CLARA L. XVEED.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

